Erin, the first hurricane of the season, exploded to a Category 5 hurricane Saturday, and despite fluctuations in intensity, the storm is remaining formidable this weekend. Here's where it could head in the week ahead.

Hurricane Erin is now a Category 5 storm, the highest on the class, rapidly intensifying overnight into early Saturday morning as it threatens the Leeward Islands and Puerto Rico, then will move along the U.

Powerful Hurricane Erin has undergone astonishingly rapid changes in its intensity — a phenomenon that has become far more common in recent years as the planet warms. It quickly became a rare Category 5 for a time Saturday,